Characterization of a bacterium of the genus Azospirillum from cellulolytic nitrogen-fixing mixed cultures

1980 ◽  
Vol 26 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Peter P. Wong ◽  
Nancy E. Stenberg ◽  
Linda Edgar
Keyword(s):  
Azospirillum Brasilense ◽  
Zea Mays L ◽  
Triticum Aestivum L ◽  
Sole Source ◽  
Andropogon Gerardii ◽  
Mixed Cultures ◽  
Big Bluestem ◽  
Azospirillum Lipoferum ◽  
Cellulose Decomposition

A bacterium with the taxonomic characteristics of the genus Azospirillum was isolated from cellulolytic N2-fixing mixed cultures. Its characteristics fit the descriptions of both Azospirillum lipoferum (Beijerinck) comb. nov. and Azospirillum brasilense sp. nov. It may be a variant strain of A. lipoferum. In mixed cultures with cellulolytic organisms, the bacterium grew and fixed N2 with cellulose as a sole source of energy and carbon. The mixed cultures used cellulose from leaves of wheat (Triticum aestivum L.), corn (Zea mays L.), and big bluestem grass (Andropogon gerardii Vitm). Microaerophilic N2-fixing bacteria of the genus Azospirillum, such as the bacterium we isolated, may be important contributors of fixed N2 in soil with partial anaerobiosis and cellulose decomposition.

Characterization of Azospirillum associated with maize (Zea mays) in France, using biochemical tests and plasmid profiles

1992 ◽  
Vol 38 (8) ◽  
pp. 798-803 ◽  
Author(s):  
Isabelle Penot ◽  
Nathalie Berges ◽  
Christine Guinguene ◽  
Jacques Fages
Keyword(s):  
Zea Mays ◽  
Azospirillum Brasilense ◽  
Zea Mays L ◽  
Specific Method ◽  
Azospirillum Lipoferum ◽  
Biochemical Tests ◽  
Plasmid Profiles ◽  
Clear Differentiation ◽  
Plasmid Profiling

Thirty Azospirillum strains were isolated from the rhizosphere of 13 maize (Zea mays L.) cultivars grown in 14 French soils, using a new specific method, which has been given the name ROSEA. Among these strains 26 were Azospirillum lipoferum and 4 were Azospirillum brasilense. Their characterization was achieved using biochemical tests and plasmid profiles. Biochemical patterns allowed clear differentiation between the two species. A large diversity in carbon source metabolism was found among the Azospirillum sp. strains regardless of their origin. The A. brasilense were much more closely related, and were found in only two of the rhizospheres studied. The 30 plasmid patterns were all different, and the plasmid-profiling technique can therefore be considered as strain specific. All the A. lipoferum harboured a 150-MDa plasmid, while all the A. brasilense harboured a 90 to 100-MDa plasmid. This result reinforces the hypothesis of the presence of such plasmids as an additional criterion for differentiating these two species. Key words: Zea mays, Azospirillum, ROSEA method, biochemical tests, plasmid profiles.

scholarly journals Realocação de nitrogênio e de biomassa para os grãos, em trigo submetido a inoculação de Azospirillum

2000 ◽  
Vol 35 (2) ◽  
pp. 401-411 ◽  
Author(s):  
AGOSTINHO DIRCEU DIDONET ◽  
OSVALDO DOS SANTOS LIMA ◽  
ANDRÉ ALESSANDRO CANDATEN ◽  
OSMAR RODRIGUES
Keyword(s):  
Triticum Aestivum ◽  
Azospirillum Brasilense ◽  
Triticum Aestivum L ◽  
Azospirillum Lipoferum

Estudou-se, em condições de campo, o efeito de inoculante turfoso em pó contendo bactérias do gênero Azospirillum no rendimento de grãos e na remobilização de N e de biomassa para os grãos de trigo (Triticum aestivum L.), cultivar Embrapa 16. Usaram-se como inoculantes, a estirpe de Azospirillum brasilense 245 e o isolado 10 de Azospirillum lipoferum. Em cada tratamento de inoculação, e também sem inoculação, aplicaram-se diferentes doses de N em diferentes estádios de desenvolvimento das plantas, distribuídos em blocos ao acaso com parcelas subdivididas. Na antese e na maturação fisiológica, avaliaram-se o acúmulo de massa seca e N total nas diferentes partes da planta. Na colheita, além do rendimento de grãos, avaliaram-se também o índice de colheita para biomassa e para N, os principais componentes do rendimento e o teor de N total de grãos. Os resultados ainda preliminares evidenciaram que, mesmo não havendo efeito da inoculação no rendimento de grãos, houve um melhor alocamento de N e de biomassa para os grãos, resultando em maior massa de mil grãos e em menor quantidade de N restante na palha das plantas na maturação fisiológica. Esses efeitos resultaram de um menor número de espigas m-2, provavelmente devido à morte de afilhos, fator que determinou maior disponibilidade de N e de biomassa às espigas e grãos restantes.

Isolation and characterization of Azospirillum mutants excreting high amounts of indoleacetic acid

1983 ◽  
Vol 29 (8) ◽  
pp. 916-923 ◽  
Author(s):  
A. Hartmann ◽  
Mahavir Singh ◽  
W. Klingmüller
Keyword(s):  
Azospirillum Brasilense ◽  
Indoleacetic Acid ◽  
Acid Metabolism ◽  
Feedback Inhibition ◽  
Growth Patterns ◽  
Wild Type ◽  
Azospirillum Lipoferum ◽  
Isolation And Characterization ◽  
Resistant Mutants

Mutants of Azospirillum brasilense Sp Cd, resistant to 5-fluorotryptophan (FT) excreted 3-indoleacetic acid (IAA), i.e., auxin, producing up to 16 μg/mL which was 30 times greater than the wild-type level. Under conditions of nitrogen fixation, the mutants excreted IAA up to 1 μg/mL, 10 times more than the wild type. However, none of the FT-resistant mutants of Azospirillum lipoferum Sp RG 20a excreted high levels of IAA. This was probably due to differences in the tryptophan and IAA biosynthetic steps between A. brasilense and A. lipoferum strains. Some of the FT-resistant mutants of A. brasilense Sp Cd showed a reduced feedback inhibition of anthranilate synthetase by tryptophan. The increased synthesis of tryptophan could explain the observed excretion of tryptophan and related metabolites. In addition, the IAA-overproducing mutants excreted other amino acids, probably owing to pleiotropic effects of deregulated tryptophan biosynthesis on amino acid metabolism. The growth patterns of some mutants excreting large amounts of IAA were almost identical to those of the wild type.

scholarly journals Characterization of Maize Genotypes (Zea mays L.) for Resistance to Striga asiatica and S. hermonthica and Compatibility with Fusarium oxysporum f. sp. strigae (FOS) in Tanzania

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1004
Author(s):  
John Lobulu ◽  
Hussein Shimelis ◽  
Mark D. Laing ◽  
Arnold Angelo Mushongi ◽  
Admire Isaac Tichafa Shayanowako
Keyword(s):  
Grain Yield ◽  
Fusarium Oxysporum ◽  
Biocontrol Agent ◽  
Zea Mays L ◽  
Control Treatment ◽  
Yield Reduction ◽  
Maize Genotypes ◽  
Significant Yield ◽  
The Mean

Striga species cause significant yield loss in maize varying from 20 to 100%. The aim of the present study was to screen and identify maize genotypes with partial resistance to S. hermonthica (Sh) and S. asiatica (Sa) and compatible with Fusarium oxysporum f. sp. strigae (FOS), a biocontrol agent. Fifty-six maize genotypes were evaluated for resistance to Sh and Sa, and FOS compatibility. Results showed that FOS treatment significantly (p < 0.001) enhanced Striga management compared to the untreated control under both Sh and Sa infestations. The mean grain yield was reduced by 19.13% in FOS-untreated genotypes compared with a loss of 13.94% in the same genotypes treated with FOS under Sh infestation. Likewise, under Sa infestation, FOS-treated genotypes had a mean grain yield reduction of 18% while untreated genotypes had a mean loss of 21.4% compared to the control treatment. Overall, based on Striga emergence count, Striga host damage rating, grain yield and FOS compatibility, under Sh and Sa infestations, 23 maize genotypes carrying farmer preferred traits were identified. The genotypes are useful genetic materials in the development of Striga-resistant cultivars in Tanzania and related agro-ecologies.

scholarly journals Enhancement of drought tolerance in Triticum aestivum L. seedlings using Azospirillum brasilense NO40 and Stenotrophomonas maltophilia B11

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Wedad A. Kasim ◽  
Mohamed E. H. Osman ◽  
Mohamed N. Omar ◽  
Samar Salama
Keyword(s):  
Triticum Aestivum ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Azospirillum Brasilense ◽  
Stenotrophomonas Maltophilia ◽  
Protein Pattern ◽  
Triticum Aestivum L ◽  
Protein Patterns ◽  
Wheat Seedlings ◽  
Enhanced Production

Abstract Background The effectiveness of two PGPB; Azospirillum brasilense NO40 and Stenotrophomonas maltophilia B11 was investigated in enhancing the drought tolerance of wheat (Triticum aestivum L.) seedlings cultivar Gemiza9. The inoculated or uninoculated grains were sown in unsterilized sandy soil and watered normally untill the 8th day. Drought stress was initiated by completely withholding water for 7 days (until wilting). Samples were collected after 15 days from sowing to evaluate some growth criteria, damage and defense indicators and to analyze the roots’ protein pattern. Results The results showed that inoculating wheat seedlings with these strains significantly diminished the inhibitory effects of drought stress on the relative water content of roots, shoots and leaves; area of leaves; contents of pigments (chlorophyll a and b) and ascorbic acid; and on the protein patterns of roots. Moreover, the bacterial inoculation notably reduced the drought-induced damage indicated by lower leakage of electrolytes and less accumulation of Malondialdehyde and hydrogen peroxide, surprisingly with less enhanced production of proline and activities of catalase and peroxidase than their uninoculated counterparts. Under normal conditions, inoculating wheat plants with these PGPB resulted in significantly promoted growth and elevated contents of pigments and altered protein patterns of roots. Conclusion Overall, we can say that both Azospirillum brasilense NO40 and Stenotrophomonas maltophilia B11 were able to deactivate the growth inhibition in wheat seedlings to some extent, while maintaining a certain level of efficient protection against damage under drought stress.

scholarly journals Characterization of phenylpropanoid pathway genes within European maize (Zea mays L.) inbreds

2008 ◽  
Vol 8 (1) ◽  
pp. 2 ◽  
Author(s):  
Jeppe Andersen ◽  
Imad Zein ◽  
Gerhard Wenzel ◽  
Birte Darnhofer ◽  
Joachim Eder ◽  
...  
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Phenylpropanoid Pathway ◽  
European Maize
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